The reason I payed the extra cash for the 3D version had more to do with our available free time than anything else. We could've made one of the earlier showings and paid matinee prices but I just didn't manage my time well enough. Nevertheless I was surprised by the experience. And what I mean by that is that it was a comfortable viewing. It almost felt like a private screening.
The movie's 3D effects were decent; they were actually more impressive during the previews. I don't know if I'll pay 3D prices again, even though my son insists that we check out the new Transformers movie in this format at the end of this month. I may do it for the relaxed atmosphere of it all and not the hyped-up graphics.